Discrete and Discontinuous Increase in the Micellar Aggregation Number: Effects of the Alkyl Chain Length on Platonic Micelles
Discrete and Discontinuous Increase in the Micellar Aggregation Number: Effects of the Alkyl Chain Length on Platonic Micelles
复制标题
胶束聚集数的离散和不连续增加：烷基链长度对柏拉图式胶束的影响
DOI：
10.1021/acs.langmuir.8b04204
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发表时间：
2019
期刊：
影响因子：
3.9
通讯作者：
Sakurai Kazuo
中科院分区：
文献类型：
--
作者：
Fujii Shota;Yamada Shimpei;Araki Masataka;Lee Ji Ha;Takahashi Rintaro;Sakurai Kazuo
最近发现的胶束在聚集数(NAG)方面具有完美的单分散性，有趣的是，其值总是与正多面体结构(即柏拉图固体)的顶点或面数重合。由于胶束的单分散性，即柏拉图胶束，我们可以预期它们将表现出前所未有的聚集行为。本研究采用小角X射线散射、不对称流动分离与多角光散射相结合的小角散射技术以及分析超速离心法研究了烷基链长对胶束聚集行为的影响。随着烷基链长的增加，柏拉图胶束的Nagg值呈不连续的离散性增加，这与常规胶束的研究结果有很大不同。这种聚集行为可以用胶束的热力学稳定性和复盖密度之间的关系来合理解释，该关系是由一个悬而未决的数学问题：Tammes问题定义的。
Micelles with perfect monodispersity in terms of the aggregation number (Nagg) have recently been discovered, whose values ofNagginterestingly always coincide with the vertex or face number of regular polyhedral structures (i.e., Platonic solids). Owing to the monodispersity of the micelles, named Platonic micelles, we could expect them to exhibit unprecedented aggregation behavior. In this study, the effects of alkyl chain length on micellar aggregation behavior were characterized using small-angle scattering techniques such as small-angle X-ray scattering and asymmetrical flow field-flow fractionation coupled with multi-angle light scattering, as well as analytical ultracentrifugation measurements. TheNaggof Platonic micelles discretely and discontinuously increased when increasing the alkyl chain length, which differs markedly from the findings for conventional micelles. This aggregation behavior could be reasonably explained by the relationship between the thermodynamic stability of the micelles and the coverage density defined by one of the unsolved mathematical problems: the Tammes problem.